1. Field of the Invention
The invention pertains to the field of model buildings. More particularly, the invention pertains to model buildings adapted for zonal pressure diagnostics simulation.
2. Description of Related Art
As a result of the current movement toward making building structures more energy efficient, there is an increasing need to train building weatherization technicians for residential and commercial buildings. Model buildings are often used in the training classes as a way of demonstrating some of the many possible construction errors, air pressure imbalances, and resulting airflow problems, as well as the testing procedures used to identify those errors and problems and energy inefficiencies. The models may also be used to teach strategies for correcting those problems.
One of the primary testing procedures performed on buildings is zonal pressure diagnostics (ZPD). ZPD involves the use of a “blower door test” in which a blower door is temporarily installed in place of an exterior door of the building being tested. The blower door seals off the doorway and has a powerful exhaust fan that depressurizes the structure. By using a manometer to compare the air pressures between various interior spaces (rooms, wall cavities, attic, basement, crawl spaces, knee walls, etc.), as well as between interior spaces and the exterior environment, and the flow rate through the blower door fan, it is possible to determine the airtightness of the building and the location of leaks.
There are also other testing procedures frequently used in pressure diagnostics. One of these procedures is duct diagnostics, which includes duct airflow balancing, checking for blocked ducts, leaky ducts, and the use of a blower door, duct diagnostic fan (a fan used to pressurize or depressurize air ducts), and air handler (furnace and/or central air conditioner) to determine leakiness of ducts to outside (also known as delta Q). Another procedure is “add-a-hole, subtract-a-hole”. This procedure quantifies the amount of leakage in a particular zone. Combustion Appliance Zone (CAZ) testing is a procedure for determining if combustion appliances (furnace, water heater, etc.) will operate safely in all conditions of weather and worst-case depressurization. Worst-case configuration is a process for determining the configuration of doors and air handlers that causes the greatest depressurization in the CAZ, which in turn can cause chimneys to back draft. Targeted air sealing uses zonal pressure diagnostic techniques to determine where to focus air-sealing measures.
Currently, the model buildings used in training classes are typically one of two types: compact human-scale models or scaled-down tabletop models.